解决方法  两个 DECLARE之间加上/  注意：/单独占用一行，且前面要顶格，无空格。

--创建容器临时表
DECLARE exist number;
begin
  select count(1) into exist  from user_tables t where t.table_name = 'TEMP_YRYD_RQ';
  if exist = 0 then execute immediate 'create table TEMP_YRYD_RQ( rqid VARCHAR2(255), rqmc VARCHAR2(255), cxtj VARCHAR2(255) )';
  end if;
  execute immediate 'delete from TEMP_YRYD_RQ';
 end; 
/
--插入数据 
DECLARE exist number;
begin
  select count(1) into exist  from user_tables t where t.table_name = 'TEMP_YRYD_RQ';
  if exist = 0 then execute immediate 'create table TEMP_YRYD_RQ( rqid VARCHAR2(255), rqmc VARCHAR2(255), cxtj VARCHAR2(255) )';
  end if;
  execute immediate 'delete from TEMP_YRYD_RQ';
 end;